With the development of communication technologies, portable electronic products such as mobile phone, handheld game player or handheld multimedia entertainment device are more and more popular. In order to facilitate realizing interaction between human and portable electronic products, linear vibration motors are usually adopted to realize functions such as incoming call prompt for mobile phones, vibration feedback for game players, and the like. However, with the improvement of the performance requirements of portable electronic products, the performance requirements to various internal components are also increased, without exception of linear vibration motors.
The conventional linear vibration motor usually includes a housing, a vibration assembly and a stator assembly, wherein the vibration assembly usually consists of a mass block, a permanent magnet and an elastic sheet. The stator assembly usually consists of an FPCB, a damping element, a stopper block and a coil. The damping element functions to control the vibration magnitude and vibration response speed of the linear vibration motor. In particular, the housing is provided with a sealed accommodation space where the vibration assembly and the stator assembly are both located. After the coil is energized, the permanent magnet drives the elastic sheet and the mass block to perform reciprocate and regular vibrations under the action of an electromagnetic push force, thus realizing the vibration function of the linear vibration motor.
The conventional damping element is usually magnetic liquid provided on the mass block. Since the damping function of the magnetic liquid is affected by the volume of the magnetic liquid and the distribution state of the magnetic liquid and it is difficult to control the magnetic liquid with strong mobility during production, the linear vibration motor using magnetic liquid as the damping element has a low yield. Also, the magnetic liquid is easy to fail after the linear vibration motor goes through reliability test such as collision test or drop test, which severely affects the vibration response performance of the linear vibration motor.